WASHINGTON — The federal Fish and Wildlife Service on Thursday declined 25 separate petitions to list a variety of species as endangered or threatened, including the high-profile Pacific walrus, which is contending with sharp climate change trends in the Arctic where it spends much of its life atop floes of floating sea ice.

The agency also declined a listing petition for the Florida Keys mole skink, a subspecies of lizard that lives on beaches and in coastal forests that face rising seas and were just swept by Hurricane Irma. The service determined that while the skink’s habitat could shrink by as much as 44 percent at the high end, most of the habitat and soils that the species needs “will remain into the foreseeable future,” at least out to the year 2060.

Other rejected listings included Bicknell’s thrush, a songbird that lives at high mountain altitudes, the Big Blue Springs cave crayfish, and the Kirtland’s snake. Fourteen separate species of Nevada springsnails were also rejected for listing.

“In making these 12-month findings, we considered and thoroughly evaluated the best scientific and commercial information available regarding the past, present, and future stressors and threats,” the agency wrote.

Gavin Shire, a spokesman for the Fish and Wildlife Service, noted that the agency has proposed to list a number of fish species, including the small but colorful candy darter, which lives in parts of Virginia and West Virginia.

But at least one environmental group thinks the petitions are being rejected too cavalierly.

“There’s a lot of opposition to endangered species protections within the Department of Interior, and this kind of blanket rejection for all these species just really highlights that,” said Noah Greenwald, who heads up the endangered species program at the Center for Biological Diversity, which requested a number of the species listings.

Greenwald said the Fish and Wildlife Service actually had to make decisions about 62 possible listings by the end of September. He said that 29 have been rejected, six species were protected, and six decisions have been delayed thus far. Twenty-one more decisions are yet to come.

Greenwald did not see a pattern in the protections and rejections, though he noted that one of the protected species, the Guadalupe fescue, is a type of grass that grows only in Big Bend National Park — meaning it doesn’t threaten any industry operations.

Similarly, the ‘i’iwi (or scarlet honeycreeper) in Hawaii was protected — its range is limited to mountaintops in Maui and the Big Island and doesn’t threaten industry, either.

In contrast, “a number of these (denied) species are threatened by climate change,” Greenwald said. They include the Florida Keys mole skink, Bicknell’s thrush and the Pacific walrus.

Stuart Pimm, a scientist at Duke University who specializes in endangered species and biological diversity, said he was struck by the many diverse ways in which some of the species at issue are affected by climate change.

“It’s an extraordinary collection of species that shout how pervasive climate change is in destroying biodiversity and, indeed, destroying natural environment,” said Pimm. “They stretch from my home in the Florida Keys all the way up to the Arctic, and they are things from rising sea level to things like the Bickle’s thrush, which is a mountaintop species. That’s how pervasive climate change now is.”

As for the failure to list any of the species, Pimm said, “it’s spectacular cowardice on the part of the Fish and Wildlife Service, who don’t have the courage to do what they are charged with doing, which is to evaluate the scientific evidence, and not kowtow to undue political pressure.”

But Shire, the Fish and Wildlife Service spokesman, countered that the rejections do not reflect skepticism regarding climate change.

“Our decisions on whether or not to list a species under the Endangered Species Act are always based on the best available science,” he said by email. “Each species is assessed individually on its merits, which include population status, trend and any conservation efforts that are underway to protect it against future declines.”

Shire added that while Trump administration officials at the Interior Department review listing decisions, “the science is undertaken by career federal biologists, who make the determination whether or not a species merits listing.”

President Donald Trump has not yet nominated a director of the Fish and Wildlife Service, which is charged with many endangered-species decisions. Others are made by the National Marine Fisheries Service of the Department of Commerce.

In the case of the Pacific walrus, perhaps the highest-profile species of the current bunch, the Fish and Wildlife Service defended the decision by arguing that the walruses “have shown an ability to adapt to sea ice loss that was not foreseen when the Service last assessed the species in 2011. Given these behavioral changes, the Service determined that it could not predict, with confidence, future behavioral responses of the species beyond 2060.”

One form of adaptation that the service discusses is that walruses could spend more time on land – something that we have seen recently with dramatic walrus haulouts along the Alaskan coast. These events have raised concerns that walruses may not be able to access food as easily, or that some individuals could be trampled in the tightly packed herds, which can number in the thousands of individuals.

“While it is likely that the increased use of land habitat will have some negative effects on the population, the magnitude of effect is uncertain given the demonstrated ability of Pacific walruses to change their behavior or adapt to greater use of land,” the service said.

The Interior Department is not the only part of government balking at some proposed endangered species listings.

On Wednesday, the House Natural Resources Committee passed five bills amending the Endangered Species Act. They include one measure allowing for the consideration of economic factors in listing decisions and another measure curtailing protections under the act for the gray wolf in Wyoming and around the western Great Lakes.

“The goal of the Endangered Species Act is to recover species,” Rep. Jack Bergman, R-Mich., said of the gray wolf during a committee meeting in September, noting that its numbers have rebounded. “Wouldn’t the limited resources of U.S. Fish and Wildlife be better utilized [for species] that are at actual serious risk of extinction?”

Many congressional Republicans view the Endangered Species Act as an outdated law used to bigfoot state-level efforts to manage wildlife. Environmentalists, meanwhile, more often than not prefer federal intervention, since they see states as more willing to cater to industry interests.

“The ESA is a landmark statute created with noble intent,” Rep. Rob Bishop, R-Utah, chairman of the House Natural Resources Committee, said in a statement Wednesday. “It also includes fatal design flaws that inhibit greater success and handicap state-led, science-based recovery strategies.”

These bills may not become law – there is a long history of trying to amend the Endangered Species Act – but, meanwhile, Pimm said he struggled to see how the 25 separate listing petitions all could fail.

“One by one, you might want to quibble,” he said. “But for all of them?”